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You are standing about 3/4 of the way up the cliff (dark blue arrow), looking in the direction of the green arrow. This is near the base of your trench (light blue arrow).

Angualr unconformity in contact of Tuap and Karmuk
Interpreted view of contact
Close up is below.

The contact between the underlying folded sediments and overlying flat-lying sediments is exposed here. It is clearly an angular unconformity, indicating that the underlying sediments were deformed and eroded prior to the deposition of the overlying sediments.

The erosional surface is not flat. It has a relief of some 10 cm. Immediately overlying the erosional surface is a concentration of pebbles, a lag deposit.

Tuap Karmuk contact at jbg 20

The rock hammer marks the unconformity. The knife marks the top of a dark brown clay that drapes the erosonal surface. There is a pebble lag at the base of this clay, and scattered fossil mollusc shells in it. The clay is overlain by interbedded fine sands and clays.

jbg sect 20 beach jbg section 65 beach chukchi sea up gully at jbg65 up gully at jbg 20 tuap and karmuk at jbg 65 karmuk at jbg 20 Cretaceous Nualvik tuap karmuk fines peat

Sources: See beginning of trip.
Part of the Athro, Limited web site.
Copyright © 1998, 2000 Athro, Limited. All Rights Reserved.
Written by Paul J. Morris
Maintained by Athro Limited
Date Created: 18 Apr 1998
Last Updated: 22 Jan 2000